Shareholders' Equity - Share Lending Agreement (Details) - $ / shares	1 Months Ended	9 Months Ended
	Jul. 31, 2018	Sep. 30, 2018
Equity [Abstract]
Borrowed shares, number issued (in shares)	7,479,431	7,479,431
Borrowed shares, public offering price per share (in usd per share)	$ 13.37